Such fruit is conventionally harvested by a shaker system that straddles a row of plants to detach the harvest. The flow of harvest obtained is then conveyed in the machine to be stored in at least one hopper provided for this purpose or in an ancillary trailer.
However, because of the action of shaker system, the flow of harvest includes, in addition to the detached fruit, notably juice, leaves, stalks, particles of wood, bunches of fruit of varied sizes.
To eliminate components other than fruit, in particular leaves and pieces of wood, harvesting machines include a cleaning device that is provided to eliminate said components from the flow by suction before storage.
Moreover, the search for quality in the field of vinification requires the elimination of green residue, notably leaf stalks, contained in the flow of harvest. However, the prior art does not satisfactorily enable such elimination in the harvesting machine.
The document FR-2 878 172 describes a system for eliminating residue from a flow of harvested grapes, said system including a sorting enclosure from which a layer of grapes and residue falls vertically, means for creating an air blade across said layer to redirect the lighter residue along a trajectory deflected relative to the trajectory along which the grapes fall, and separation means disposed downstream of the means for creating an air blade in order to separate the deflected trajectories of the residue and the falling grapes.
This system is not entirely satisfactory, however, in that a substantial part of the residue may not be deflected. The air blade is characterised by a large width and a very small height. Consequently, elongate elements such as leaf stalks that have assumed a vertical position on passing in front of said air blade are not deflected relative to the other elements. Moreover, during this passage, the layer of harvest is in free fall. The speed of the product is therefore too high relative to the height of the blade to enable satisfactory deflection of the residue. Finally, the relative position of the falling elements may lead to a leaf stalk being masked by surrounding grapes with the result that the air blade is unable to separate them.